Taeko Murakami

Fluoride distribution and histological structure of human cementum

Thirty-one teeth taken post-mortem from 10 subjects aged from 40 to 66 years were studied. A close relationship was found between fluoride (F) distribution and histological structure. Although, as in all mineralized tissues, F concentrations tended to be highest towards the external surface, individual patterns of F distribution also seemed to reflect the histological pattern, especially the distribution of cellular or acellular cementum. In general, F concentrations were high in acellular and low in cellular cementum.

Fluoride intake in Japanese children aged 3-5 years by the duplicate-diet technique

This study was conducted to determine the fluoride intakes in 94 preschool children aged 3, 4 and 5 (n = 30, 30, 34, respectively) residing in Yokkaichi, Mie Prefecture (< 0.16 ppm F water supply). The parents duplicated all the diets that their children ingested on 3 separate days during a 1-year period. The acid-diffusible fluoride in the diet was isolated by the acid-diffusion technique and measured with a fluoride electrode. The mean daily fluoride intakes from diet alone by children aged 3, 4 and 5 were 0.30 mg (n = 29, SD 0.19), 0.28 mg (n = 30, SD 0.19) and 0.30 mg (n = 34, SD 0.19), respectively. The total estimated mean values from diet and dentifrice were 0.35 mg (n = 29, SD 0.22, range 0.13–1.00), 0.33 mg (n = 30, SD 0.19, range 0.13–0.86) and 0.39 mg (n = 34, SD 0.18, range 0.18–1.01), respectively. It was concluded that the mean (±SD) total fluoride from diet and dentifrice in 3- to 5-year-old Japanese children was 0.35 ± 0.19 mg/day (0.021 ± 0.012 mg/kg body weight).

The distribution pattern of fluoride concentrations in human cementum.

The distribution of fluoride across human cementum has been determined on 59 individual teeth taken post mortem from five subjects aged 30, 43, 54, 66 and 70 years. Eight teeth of different types were examined from each of the five subjects together with a further 19 teeth from the 54-year-old, making a total of 27 teeth from this subject. As in a previous study, F concentrations were generally higher towards the surface of the cementum, but there were considerable variations between F gradients. The teeth from each subject seemed to comprise a family of profiles, characteristic of the individual.

Relationships between mandibular cortical bone measures and biochemical markers of bone turnover in elderly Japanese men and women

OBJECTIVE The aim was to clarify the association between dental panoramic radiography measures of mandibular inferior cortical shape and biochemical markers of bone turnover in elderly men and women. STUDY DESIGN Subjects were 80-year-old men (n = 85) and women (n = 153). Mandibular cortical shape and width were evaluated on dental panoramic radiographs. Bone formation and resorption, respectively, were estimated by serum levels of carboxy-terminal propeptide of type I collagen (PICP) and serum type I collagen carboxy-terminal telopeptide (ICTP). RESULTS Eroded cortices of the mandible were significantly associated with increased serum PICP levels (P = .005) in women. Lower mandibular cortical width quartiles were also significantly associated with increased serum PICP levels in men (P = .020) and women (P = .006). CONCLUSIONS Mandibular inferior cortical measures detected on dental panoramic radiographs may be associated with bone formation rates and be useful in predicting osteoporosis in elderly Japanese men and women.

Assessment of oral malodor and tonsillar microbiota after gargling with benzethonium chloride

The oropharyngeal area can be a source of halitosis. However, the relationship between healthy tonsillar microbiota and halitosis is poorly understood. We conducted a pilot clinical study to clarify the effect of gargling with an antiseptic agent on tonsillar microbiota in patients with halitosis. Twenty-nine halitosis patients who did not have otolaryngologic disease or periodontitis were assigned randomly to one of three groups: benzethonium chloride (BZC) gargle; placebo gargle; no gargle. Concentrations of volatile sulfur compounds (VSCs) in mouth air, the organoleptic score (ORS) and tongue-coating score (TCS) were measured before and after testing. Tonsillar microbiota were assessed by detection of periodontal pathogens, and profiling with terminal-restriction fragment length polymorphism (T-RFLP) analysis and sequencing of 16SrRNA clone libraries for taxonomic assignment. Gargling with BZC reduced the concentrations of methyl mercaptan and hydrogen sulfide and the ORS, but did not affect the TCS or prevalence of periodontal pathogens. T-RFLP analyses and 16SrRNA clone sequencing showed a tendency for some candidate species to decrease in the test group. Although gargling of the oropharyngeal area with an antiseptic agent can reduce oral malodor, it appears that tonsillar microbiota are not influenced greatly. (J Oral Sci 58, 83-91, 2016).

Influence of beverage and food consumption on fluoride intake in Japanese children aged 3-5 years.

This study was conducted to estimate the relative contribution of particular foods and drinks to dietary fluoride intake in 94 preschool Japanese children in low-fluoride areas. The mean daily fluoride intake from all beverages (548 ± 162 g) was 0.108 mg (SD = 0.082), accounting for 37% of the total dietary fluoride; tea beverages showed the highest value, 0.093 mg (SD = 0.081), 32%. That from staple food and side dishes was 0.183 mg (SD = 0.146), 63%, followed by cereals (12%), fish (8%) and bean products (5%). In conclusion, the contribution of beverages excluding tea to dietary fluoride intake is small in Japanese children.